Mg. Hawkins et Jd. Mcghee, ELT-2, A 2ND GATA FACTOR FROM THE NEMATODE CAENORHABDITIS-ELEGANS, The Journal of biological chemistry, 270(24), 1995, pp. 14666-14671
We have previously shown that a tandem pair of (A/T)GATA(A/G) sequence
s in the promoter region of the Caenorhabditis elegans gut esterase ge
ne (ges-1) controls the tissue specificity of ges-1 expression in vivo
. The ges-1 GATA region was used as a probe to screen a C. elegans cDN
A expression library, and a gene for a new C. elegans GATA-factor (nam
ed elt-2) was isolated. The longest open reading frame in the elt-2 cD
NA codes for a protein of M(r) 47,000 with a single zinc finger domain
, similar (approximately 75% amino acid identity) to the C-terminal fi
ngers of all other two-fingered GATA factors isolated to date. A simil
ar degree of relatedness is found with the single-finger DNA binding d
omains of GATA factors identified in invertebrates. An upstream region
in the ELT 8 protein with the sequence C-X(2)-C-X(16)-C-X(2)-C has so
me of the characteristics of a zinc finger domain but is highly diverg
ed from the zinc finger domains of other GATA factors. The elt-2 gene
is expressed as an SL1 trans-spliced message, which can be detected at
all stages of development except oocytes; however, elt-2 message leve
ls are 5-10-fold higher in embryos than in other stages. The genomic c
lone for elt-2 has been characterized and mapped near the center of th
e C. elegans X chromosome. ELT-2 protein, produced by in. vitro transc
ription-translation, binds to ges-1 GATA-containing oligonucleotides s
imilar to a factor previously identified in C. elegans embryo extracts
, both as assayed by electrophoretic migration and by competition with
wild type and mutant oligonucleotides. However, there is as yet no di
rect evidence that elt-2 does or does not control ges-1.